Flat drying,wet wrinkle resistant finish for cellulosic textile materials



United States Patent 3,508,860 FLAT DRYING, WET WRINKLE RESIST- ANT FINISH FOR CELLULOSIC TEX- TILE MATERIALS William Julius Van Loo, Jr., Rye, N.Y., and Samuel James OBrien, Dunellen, N.J., assignors to American Cyariamid Company, Stamford, Conn. a corporation of Maine No Drawing. Filed Aug. 25, 1966, Ser. No. 574,900 Int. Cl. D06m 13/00 U.S. Cl. 8120 4 Claims ABSTRACT OF THE DISCLOSURE A new use process of applying a polyhalotetrahydrothiophene 1,1-dioxide to a cellulosic substrate to produce a flat-drying, wet-crease resistant cellulosic textile material such as fibers, yarns, and fabrics.

This invention relates to a new use process of applying a polyhalotetrahydrothiophene-1,1-dioxide to a cellulosic substrate to produce a flat-drying, wet-crease-resistant cellulosic material such as fibers, yarns, and fabrics.

The art of fiat drying is typically discussed in U.S. Patent No. 2,985,501.

Although significant advances have been made in the processes and fabrics obtained thereby relating to permanent crease and crease-resistance, there is a continued emphasis on the discovery of new and improved processes and fabrics obtained thereby which overcome some of the problems associated with current processes and fabrics.

As is true with the employment of any textile finish, it is of practical commercial importance that the treated material retain a softness of hand, good tensile strength, resistance to chlorine, and of particular importance, resistance to discoloration as a result of scorching.

It is an object of this invention to obtain a process for imparting flat drying properties to a cellulosic substrate.

Another object is to obtain a treated substrate having flat drying properties.

Another object is to obtain a fiat drying, crease-resistant fabric of high tensile strength.

Another object is to obtain a fabric resistant to chlorine deterioration.

Another object is to obtain a cellulosic fabric resistant to scorching discoloration.

Another object is to obtain a process for imparting wet wrinkle resistant properties to a cellulosic substrate.

Another object is to obtain a treated cellulosic substrate having wet wrinkle resistant properties.

Other objects become apparent from above and following disclosures.

It has been discovered that the above objects may be substantially obtained by applying a polychlorotetrahydrothiophene 1,1-dioxide (in a suitable vehicle) to a cellulosic substrate. The process includes (1) the treating of the cellulosic substrate with the above composition, (2) preferably drying the treated substrate, (3) thereafter applying an aqueous solution of an alkali metal hydroxide, preferably a hydroxide of sodium or potassium or mixtures thereof, in an amount sufficient to at least moisten said treated substrate, (4) continuing to maintain said treated substrate (a) in at least a moist state, preferably a wet state, and (b) preferably concurrently in the absence of air, for a period sufficient for a reaction to take place (the necessary period is at least about 1 minute at higher temperatures and longer at lower temperatures), at a reaction temperature at least sufiiciently high (elevated) for reaction to take place with the cellulosic substrate, normally at a temperature ranging fom about room temperature of about 60 F. to about 80 F. up to a maximum temperature of about 250 F., (5) removing at least a substantial amount of any unreacted hydroxide, by any suitable means, (21) preferably by washing with preferably water or with other aqueous washing media and/or (b) by applying to said swelled substrate an acid of substantially low hydrogen ion concentration, sufiiciently to neutralize said substantial amount of unreacted hydroxide and thereafter removing, preferably by aqueous washing, at least a substantial amount of residual acid on the treated substrate. In the preferred embodiment, the hydroxide-treated substrate is both (1) washed to remove residual hydroxide, (2) treated with acid, and (3) thereafter again washed to remove residual acid.

Instead of first treating the substrate with the polychlorotetrahydrothiophene 1,1 dioxide and thereafter treating the substrate with the hydroxide, the order of treatment may be reversed, whereby the substrate is first treated with the hydroxide and thereafter with the polychlorotetrahydrothiophene 1,1-dioxide.

Suitable vehicles for the polychlorotetrahydrothiophene 1,1-dioxide typically include conventional solvents such as acetone, dimethylformamide, benzene, tetrahydrofuran, toluene, xylene, etc., but may also include carriers in which a suitable emulsion may be formed prior to the applying step. The chlorinated hydrocarbons such as ethylene dichloride, tetrachloroethane, and carbon tetrachloride are other typical examples of a suitable vehicle.

The temperature at which the treated substrate is maintained in at least moist condition, for at least about 1 minute, preferably does not exceed 190' F. A temperature in excess of the maximum temperature of about 250 F. may be expected to cause discoloration, or other complications.

The polychlorotetrahydrothiophene 1,1-dioxide may be employed in any amount sufficient to obtain the degree of fiat drying and crease-resistant properties desired. However, in the preferred embodiments, about 10% to about 20% by weight of the solution is employed, the broad range normally extending from about 1% to about 50%.

The method of applying the polychlorotetrahydrothiophene 1,1-dioxide may be any method whereby the cellulosic substrate becomes coated or impregnated, such as conventional padding, dipping, and spraying procedures. In the typical padding procedure, for example, the wet pick up is about The concentration of hydroxide may be varied as desired and as dependent upon the nature of the cellulosic substrate being treated. Normally, however, the typical hydroxide solution may be in the vicinity of about 20% aqueous solution of sodium hydroxide, for example.

The preferred substantial absence of air during the reaction period following the hydroxide treatment avoids the possibility of a loss of caustic (hydroxide) with a consequent loss in potential swelling of the treated substrate; the loss of caustic could result from the reaction of the hydroxide with carbon dioxide in the air. This would not constitute a problem, however, when higher reaction (swelling) temperatures are employed, within the above stated limits. It should additionally be noted that one advantage of the composition of this invention arises from the fact that the composition is not volatile at temperatures up to about 200 C. (about 400 F.).

In the above embodiment, the hydrogen ion concentration is sufficiently low to avoid damage to the substrate, but also sufiiciently high to neutralize an adequate amount of residual hydroxide on the substrate.

The acid in the final rinsing step may typically be a dilute solution of a strong acid such as HCl, H 50 H PO etc., and/or a stronger solution of one or more weak acids such as acetic, formic, propionic, etc.

In order to obtain the objects of this invention, it is critical that there be at least two chlorine substituents on 3 the tetrahydrothiophene 1,1-dioxide. In the broadly preferred embodiments of this invention, the composition includes dichlorotetrahydrothiophene l,l-dioxides and tetrachlorotetrahydrothiophene l,l-dioxides, the preferred TABLE I Percent sulfur on Percent compound found on Wrinkle recovery abric fabric by S analysis (W-i-F in degrees) Percent fixed After After on Fabric condition Initial boil Initial boil fabric Dry Wet Treated 1. O6 0. 76 6. 24 4. 47 72 158 218 Untreated 139 167 embodiment being a 3,3,4,4-tetrachlorotetrahydrothiophene 1,1-dioxide.

It is within the scope of this invention to employ conventional methods of synthesis of the compounds employed in this invention. Typical of the methods suitable for the synthesis of polychlorotetrahydrothiophene 1,1- dioxides are those described in the Journal of the American Chemical Society (1949), vol. 71, page 1875, which discloses a method of preparation of 2,5-dihydrothiophene 1,1-dioxide (also known as butadiene sulfone) and 3,4- dichlorotetramethylene sulfone (also known as 3,4-dichlorotetrahydrothiophene 1,1-dioxide). The butadiene sulfone is therein disclosed as prepared by the reaction of butadiene with sulfur dioxide at about 100 C. A second publication, the Journal of Organic Chemistry (1961) vol. 26, page 346, discloses a similar reaction of butadiene with sulfur dioxide, followed by chlorination of 2,5-dihydrothiophene 1,1-dioxide to finally obtain the 3,4-dichlorotetrahydrothiophene 1,1-dioxide (also known as 3,4-dichlorotetramethylsulfone) and 3,3,4,.4-tetrachloro tetrahydrothiophene 1,1-dioxide.

The following examples are intended to solely illustrate the above disclosed invention and are not intended to limit the scope of the invention except insofar as such limitations appear in the appended claims.

EXAMPLE 1 Cotton percale (80 x 80) was treated through a bath prepared from acetone containing 29 parts of 3,4-dichlorotetrahydrothiophene 1,1-dioxide. The fabric was squeezed on a micro-set padder to approximately 85% wet pick up, equal to 24.7% of the thiophene compound on the fabric. After drying at room temperature, the treated fabric was squeeze padded through a aqueous solution of sodium hydroxide, folded and wrapped in polyethylene film. The folded wet fabric was placed under weights of undetermined pressure and allowed to stand at room temperature for 24 hours. After standing, the fabric was water rinsed and then subjected to an aque- Results show good fixation of the compound with considerable improvement in wet wrinkle recovery when compared to the untreated fabric.

EXAMPLE 2 TABLE II Wrinkle recovery (W+F in degrees) Fabric condition Dry Wei;

Treated 153 232 Untreated 140 155 Good wet wrinkle recovery is shown. (This is considerably better than the compound of Example 1.)

EXAMPLE 3 Cotton percale x 80) is treated with baths containing varying amounts of 3,4-dichlorotetrahydrothiophene 1,1-dioxide in acetone. The fabric is squeezed on a microset padder to approximately wet pick-up thus depositing upon the fabric samples varying amounts of compound. After drying at room temperature, the treated fabric samples are squeeze padded through a 20% aque' ous solution of sodium hydroxide, folded and wrapped in polyethylene film. The folded wet fabric is placed under Weights of undetermined pressure and allowed to stand at room temperature for 24 hours. After standing, the fabric is rinsed with water, then rinsed with dilute (0.5%) acetic acid, and finally rinsed with water again. After drying at room temperature, tests for wet and dry wrinkle recovery and sulfur content are made as in Example 1. Results are as follows:

TAB LE III Percent compound on fabric calculated Percent sulfur on fabric from percent 5 Wrinkle recovery Percent compound After After Fixed in bath Initial Boil Initial Boil Percent Dry Wet ous acidic rinse containing 0.5% acetic acid and then given a final rinse in water only and then air dried.

Analytical tests for sulfur content were performed on Results show that improvement in wet wrinkle recovery increases with increasing amounts of compound applied. The amount of compound fixed to fabric also increases the treated fabrics initially and after a 30 minutes boil in 75 with increasing amount applied.

EXAMPLE 4 A sample of cotton percale treated with 30% compound in the bath according to Example 3 was subjected to chlorine bleaching tests in accordance with AATCC 6 an amount suificient to deposit from about 1.0% to about 50% by weight of said compound on said cellulosic textile material, (2) immediately thereafter maintaining said cellulosic textile material at a temperature in the range of 60 F. to 250 F. for at least about one Tentative T st M th d 9 9 The following results minute under conditions which retain substantially all of were obtained. the moisture arising from said aqueous solution and there- TABLE IV Tensile Strength, lbs. W+F Color (visual) Scorched Scorched Unscorched Unseorched Initial Initial Chlorinated Initial Initial Chlorinated Treated 78 78 79 White White White Untreated 105 103 104 White White White Results show that while some loss of strength occurs after subjecting said cellulosic textile material to aqueous as a result of fabric treatment with 3,4-dichlorotetrarinses. hydrothiophene 1,1-dioxide, no additional loss occurs due 2. A cellulosic textile material treated according to to scorching alone or due to scorching following chloclaim 1. rine bleaching. In addition, scorching alone or scorch- 3. The process of claim 1 in which said organic solvent ing after chlorine bleaching does not cause discoloration solution of polychlorotetrahydrothiophene 1,1-dioxide is of the treated fabric. These results indicate that the treatseparately applied in a first step and the solvent is allowed ment may be advantageously employed as a finish for to evaporate from the thus-treated cellulosic textile matefabric subjected to chlorine bleaching. rial before subsequent treatment with the aqueous alkali The above example and disclosure are intended to demetal hydroxide solution. scribe and illustrate the invention. However, the scope 4. The process of claim 1 wherein the polychlorotetraof the invention is limited only to the extent that limitahydrothiophene 1,1-dioxide is 3,3,4,4-tetrachlorotetrahytions appear in the appended claims. It is within the drothiophene 1,1-dioxide. scope of this invention to employ such equivalents and substituents as would be obvious to an artisan of ordi- References Cited 1118 UNITED STATES PATENTS e c arm:

1. A process for producing flat-drying, wet-wrinkle re- ,ieldmann 8-416 XR sistant cellulosic textile materials which comprises (1) 3402988 9/196 Rauss 8-120 separately contacting said cellulosic textile material with 8 eaves et 8 120 (a) an aqueous solution of a member selected from the group consisting of sodium hydroxide and potassium hydroxide and (b) a solution of polychlorotetrahydrothiophene 1,1-dioxide in an organic solvent therefor and in JOHN DAVID WELSH, Primary Examiner US. Cl. X.R. 8116; 117-1394 

